have a new furnace for several yrs. now and i no longer have a humidifier. finally getting around to removing humidifier controller. Question: there are 2 wires, 1 red, 1 white, attached to the humidifier controller on the wall. can i cut the wire & shove it back into the wall since it's impossible for it to be attached to a non-existent humidifier and furnace? or, should i wrap the wire in elec. tape, cap & then put wire back into wall?
First, you're dealing with low-voltage wiring. There's no real risk of shock or fire. For that reason you can do as you like.
The only real risk is of a short, which could potentially damage circuitry or just waste power. However, I'm guessing that the power supply for this circuit was at the furnace, or there's a battery in the controller. Since you've removed the furnace unit, check for a battery and remove it, then carry on.